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... Tycho developed a system that
combined the best of both worlds.
He kept the Earth in the center of
the universe, so that he could
retain Aristotelian physics and
Ptolemy’s geocentric idea.
The Moon and Sun revolved about the Earth, and
the shell of the fixed stars was centered on the
Earth.
But Merc ...

... Student of Plato who built philosophy based on
observation, induction of general principles. Theory of
causes determined motion and material of celestial objects.
Aristarchus of Samos
310 B.C. – 230 B.C.
Determined the distance from the earth to the moon and sun
(correct method, incorrect results), ...

... Earth, Space and all that jazz…
A long time ago, in the second century,
There was a Greek astronomer called Claudius Ptolemy.
Who came up with a theory called the geocentric model,
Which made the Earth the focal point and centre of it all.
Centuries went past before some began to doubt.
‘We simply d ...

...  200 A .D.
 Librarian of Alexandria
 Believed Heraclides’ geocentric model of the solar system to
be correct
 His model seemed to adequately explain the motion of the
planets, but it was complicated.
...

... Earth is at the center of the Universe. So
the Sun, Moon, Stars and Planets are all
revolving around Earth.
In the Geocentric Model, Earth does not
move, it doesn’t even rotate.
Who was the first scientist to say that the
Earth is not the center of the Solar System,
but the Sun?
 Copernicus was fir ...

... The sphere outside the moon orbit. The heavenly
spheres which comprise the fifth, divine element, the
aether. Here everything moves in perfect circles. No
irregularities exist. All fixed stars and the planets exist
in this sphere.
...

... • Sometimes the eccentric was slightly off center from the center of the Earth
Ptolemy’s Geocentric Model
• Uniform circular motion could not account for speed of the planets thus
Ptolemy used a device called the equant
• The equant was placed the same distance from the eccentric as the Earth,
but o ...

... Reasons for Theories of Geocentricity
• Claudius Ptolemy of Alexandria (150 AD)
– Utilised the geocentric model, that earth was the
center of the universe, to predict with far greater
accuracy the motions of known celestial bodies. This
reinforced the idea of geocentricity over heliocentricty
among ...

... The planets (Mercury, Venus, Mars, Jupiter and Saturn) appeared only as
points of light on the sky, like the stars, but unlike the Sun and Moon. These
objects received special attention because they:
 moved against the background of stars,
 are always located within several degrees of the ecliptic ...

Geocentric model

In astronomy, the geocentric model (also known as geocentrism, or the Ptolemaic system) is a description of the cosmos where Earth is at the orbital center of all celestial bodies. This model served as the predominant cosmological system in many ancient civilizations such as ancient Greece including the noteworthy systems of Aristotle (see Aristotelian physics) and Ptolemy. As such, they believed that the Sun, Moon, stars, and naked eye planets circled Earth.Two commonly made observations supported the idea that Earth was the center of the Universe. The stars, the sun, and planets appear to revolve around Earth each day, making Earth the center of that system. The stars were thought to be on a celestial sphere, with the earth at its center, that rotated each day, using a line through the north and south pole as an axis. The stars closest to the equator appeared to rise and fall the greatest distance, but each star circled back to its rising point each day. The second observation supporting the geocentric model was that the Earth does not seem to move from the perspective of an Earth-bound observer, and that it is solid, stable, and unmoving.Ancient Roman and medieval philosophers usually combined the geocentric model with a spherical Earth. It is not the same as the older flat Earth model implied in some mythology, as was the case with the biblical and postbiblical Latin cosmology. The ancient Jewish Babylonian uranography pictured a flat Earth with a dome-shaped rigid canopy named firmament placed over it. (רקיע- rāqîa').However, the ancient Greeks believed that the motions of the planets were circular and not elliptical, a view that was not challenged in Western culture until the 17th century through the synthesis of theories by Copernicus and Kepler.The astronomical predictions of Ptolemy's geocentric model were used to prepare astrological and astronomical charts for over 1500 years. The geocentric model held sway into the early modern age, but from the late 16th century onward was gradually superseded by the heliocentric model of Copernicus, Galileo and Kepler. There was much resistance to the transition between these two theories. Christian theologians were reluctant to reject a theory that agreed with Bible passages (e.g. ""Sun, stand you still upon Gibeon"", Joshua 10:12 – King James 2000 Bible). Others felt a new, unknown theory could not subvert an accepted consensus for geocentrism.